Dorfmanite is a rare phosphate mineral typically found in hyperagpaitic rocks within alkaline igneous complexes. It usually occurs as fragile, colorless to white tabular crystals that are highly sensitive to humidity and can dehydrate if stored improperly.
Is this dorfmanite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch dorfmanite with a known reference. Dorfmanite sits at Mohs 1-1.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous to earthy.
- 4Match the color rangeCompare against the expected color range: white.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: aggregates, powdery, very soluble.
Often confused with
Dorfmanite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside dorfmanite
Minerals reported to co-occur with dorfmanite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₂HPO₄·2H₂O
- Mohs hardness
- 1-1.5
- Density
- 1.98-2.00 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous to earthy
- Transparency
- Semitransparent
- Crystal system
- Orthorhombic
- Crystal habit
- Aggregates, powdery, very soluble
- Cleavage
- Indistinct
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Noted in drill cores into alkalic pegmatites in differentiated alkalic massifs, as an alteration product of lomonosovite and nacaphite (Kola Peninsula, Russia)
Where rockhounds find dorfmanite
Classic worldwide localities
- Kola Peninsula, from Mts. Yukspor, Kukisvumchorr, Koashva, and Rasvumchorr in the Khibiny massif, and on Mts. Karnasurt and Alluaiv in the Lovozero massif, Russia
- Mont Saint-Hilaire, Quebec, and in the Tanco pegmatite, Bernic Lake, Manitoba, Canada
Field-hunting tip
Where it forms: Noted in drill cores into alkalic pegmatites in differentiated alkalic massifs, as an alteration product of lomonosovite and nacaphite (Kola Peninsula, Russia). If you start seeing lomonosovite, olympite, villiaumite in float, you are in the right ground. Typical habit: aggregates, powdery, very soluble. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify dorfmanite?+
Where is dorfmanite found?+
What rocks look like dorfmanite?+
What minerals are found with dorfmanite?+
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What is dorfmanite used for?+
Find dorfmanite on the map
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